Serum sialic acid in patients with oral cancer

We measured serum sialic acid in oral cancer patients by enzymatic method.The mean serum level of sialic acid in the patients was significantly higher than that in normal volunteers, and the level was proportional to the stage of cancer. In most patients, serum levels of sialic acid returned to normal postoperatively. However, in patients with recurrence or metastasis, the levels rose gradually after surgery.Serum levels of sialic acid were well correlated with those of aracid glycoprotein and ar macroglobulin. In addition, we found that O2- production of neutrophils was inhibited by sialic acid.From these results, the measurement of serum sialic acid in oral cancer seems to be useful to estimate of progress, recurrence and metastasis. It is also suggested that sialic acid has deep connection with neutrophil's function.